


Thank You For The Music

by MontagueBitch (porcia_catonis)



Category: Shadowhunters (TV), The Mortal Instruments Series - Cassandra Clare, The Shadowhunter Chronicles - All Media Types, The Shadowhunter Chronicles - Cassandra Clare
Genre: Alternate Universe - Canon Divergence, Cursed Object, Gen, M/M, Magic, Musical Comedy, Pre-Episode: s01e12 Malec
Language: English
Status: In-Progress
Published: 2018-05-26
Updated: 2018-05-25
Packaged: 2019-05-13 21:32:54
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,201
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/14756699
Author URL: https://archiveofourown.org/users/porcia_catonis/pseuds/MontagueBitch
Summary: A book that may make Valentine Morgenstern trackable lays inside the tomb of a mad warlock of old. However, the book has been booby-trapped: any who touch it must express their innermost feelings via song, and may continue until it returns to rest. Set between 1x11 and 1x12.





	Thank You For The Music

Magnus Bane was knelt in a crypt, holding a book covered in cobwebs, and feeling extremely weird. He had paused, and said nothing since he picked up the book that just might make him able to track an untrackable madman. Isabelle stood outside, reading the tombstone. CURST BE HE THAT VEILS HIS HEART. It was, she thought, a strange thing to put on a grave. But then, so had the sheer number of traps that this crypt contained. Strangeness, however, was what Isabelle existed for. To fix it, to understand it, and, if it was dangerous, to kick its ass. None of that mattered now, of course, if Magnus had the book.

“Is that it? You’ve got it?” Alec’s voice, tight distant carries through the room, though it’s said over his shoulder. The guard demons had all been dispatched, but he hadn’t yet dared lower his bow. Something told him the traps and shenanigans they’d faced in order to get here wasn’t over.

Some part of him, a part of him that knew fear and selfishness above all else, couldn’t help hoping that the worst wasn’t over, and he’d be knock unconscious or otherwise unwell for at least seventy-two hours. He had his reasons.

“Unless this book labeled The Book of Alastor Frost, and the only thing in this chest, is not, in fact, The Book of Alastor Frost—I’d say it’s safe to assume I’ve got it, Alexander.”

“It happened in Harry Potter. R.A.B.’s locket. It wasn’t the Horcrux they were looking for.” Alec stared at Simon, blank, and maybe a bit tired.  “What it was, was a replica of the Horcrux. He had the real one hidden in plain sight, so the quest was wasted, and Dumbledore drank the poison for nothing. Just saying.” Alec looked no less exhausted as Simon continued.

“Why did we bring the vampire?”

“Because,” Izzy, as ever, made it a point to defuse this before bridges burned and the ropes that held them snapped, “Simon doesn’t want Valentine to get the cup, either. And, so I’ve read, this book might have a spell to make vampires immune to daylight. He’s got a need for it, too, big brother.” She didn’t need to mention that they needed all the help they could get with Jace not speaking to his _parabatai._ It was either Alec went, or Jace went, and Jace wasn’t dodging a wedding to plan. So while the rest of them went, Jace remained in the institute, left in unawares.

“Speaking of interests in this,” An eye roll from Magnus, still crouched in the empty crypt, book in hand and cobwebs on his well-pressed trousers, “Someone help me up.”

Alec lowered his bow at that, and with an exchange of glances, Isabelle took her brother’s place standing watch. “Hand me the book,” he held out a hand, and when he took it from Magnus, he set it on the ground beside him. Then, he took the warlock’s hand and pulled him back above ground with the rest of them. When Magnus had caught his balance again, Alec still hadn’t dropped his hands, and they stayed there for a moment private enough that Simon looked away. Magnus was the first to drop hands, stiff armed.

“Thank you.” Magnus was stiff, and a bit pale, with his jaw clenched. Isabelle swore he looked like he was trying very hard to hold something back. He didn’t say anything more, and he began to draw a portal back to the Institute’s Sanctuary.

“Are you—Magnus, what’s wrong?” Alec seemed to notice something off, too, and his brows knit together, his face somewhere between hurt and concern. While Alec stared, puzzled and frustrated, Clary picked up the Book, so this wouldn’t be a portal made, and people lied to, for nothing.

He didn’t get a reply, only a tight-lipped—literally, it looked like—gesture to the portal. Alec froze for a moment, and then went through. Isabelle followed, and as she stepped aside, home again, the others followed.

Not quite out of earshot, she heard her brother’s low voice, insistent, “Please, just tell me what’s on your mind.”

Magnus’ eyes widened for a moment, as though surprised at what he did next. Isabelle couldn’t say she blamed him. There was no further preamble. “ _I wasn’t jealous before we met_ ,” the words came out in song—one Simon and Clary identified almost immediately. “ _Now every woman I see is a potential threat!_ ” As the words fell, Magnus’ body moved, circling Alec in a strangely choreographed matter as Lay All Your Love On Me carried through the catacomb.  Alec, all the while, did not seem to be reacting with the same awestruck bemusement the rest of them had been uniformed in. Rather, he had the biting-something-back look on his face that Magnus had early, but for the second verse, it bust from him.

Isabelle was fairly certain, whatever her brother liked in music, it wasn’t ABBA. Somehow, though, from her brother’s mouth “a little small talk and a smile and baby, I was struck. I still don’t know, what you’ve done with me,” seemed to make sense in a way that Magnus—the real Magnus, and not the song-Magnus, registered, too.

They both joined the chorus, now joined in a dance that should never have been possible for two unrehearsed, untrained performers who were not, in fact, performers.

And so they went, harmonizing, sharing verses, lines, and so on until one final chorus: “ _Don’t go wasting your emotion,”_ Alec, dismissive, seemed to dance away, but the next line was for both of them. “Lay all _your love on me!”_

“ _Don’t go sharing your devotion,”_ Magnus, this time. He grabbed Alec’s retreating hand, and her brother spun into Magnus’s arms, head turned with their faces just inches apart. Isabelle might have sworn the lyric was eerily well-placed, chosen by some cruel god with a sense of irony. Or demon, more likely “ _Lay all your love on me!”_ the finished in unison, finally left panting, and confused beyond belief. Isabelle had never seen a musical performed, but this was what she often pictured one must contain, alongside some kind of turning point.  

“What just happened?” Alec, back to himself, looked to Magnus searchingly, and a moment later gaining the presence of mind to spin back, once again, out of his arms. Isabelle was thinking the same thing, if truth be told. Something about that inscription, the one she’d seen in the tomb, kept coming to mind. She didn’t know enough about this all to say anything, not yet, but the seed of suspicion had been planted that the nature of the curse had something to do with that message. What, beyond that, any of this sprang from, she was drawing blank.

Magnus was about to speak again when the door to the Sanctuary swung open wide, and Maryse Lightwood strode in, her husband only a few steps behind. Her eyes swept over her son and the High Warlock of Brooklyn, each out of breath. Then it brushed across the rest of them, all staring, too, at the ghost of a finished duet.

“What,” she asked, “is going on in here?”

**Author's Note:**

> Firstly, blame my GF and the film Mamma Mia! (2008) for this. Secondly, If you've got a character/song combination you'd like to see (ABBA or not!), please tell me in the comments. You just might see it in a later installment!


End file.
